Arthritis of the hip joint and osteoporosis can be crippling conditions, and this incidence both alone and combined is significant both economically and socially. Total hip replacement by prosthesis is well established as a method of treatment of arthritis, but failures occur, some of which are related to the bone-cement interface, and presumably therefore to the "quality" of the pre-existing bone. We are attempting to quantify the bone parameters of the upper femur including elasticity, compact bone density and bone mineral content using a modification of our ultrasonic technique, already proved to be successful in assessing the same parameters in the proximal radius. This work is expected to have a bearing on the prediction of implant success, possible modification of implant techniques and design of prosthetic components, and will add to our knowledge of the distribution of osteoporosis throughout the skeleton.